| 1 | /* |
| 2 | * LucasArts VIMA decoder |
| 3 | * Copyright (c) 2012 Paul B Mahol |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file |
| 24 | * LucasArts VIMA audio decoder |
| 25 | * @author Paul B Mahol |
| 26 | */ |
| 27 | |
| 28 | #include "libavutil/channel_layout.h" |
| 29 | |
| 30 | #include "adpcm_data.h" |
| 31 | #include "avcodec.h" |
| 32 | #include "get_bits.h" |
| 33 | #include "internal.h" |
| 34 | |
| 35 | static int predict_table_init = 0; |
| 36 | static uint16_t predict_table[5786 * 2]; |
| 37 | |
| 38 | static const uint8_t size_table[] = { |
| 39 | 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, |
| 40 | 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, |
| 41 | 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, |
| 42 | 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, |
| 43 | 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, |
| 44 | 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7 |
| 45 | }; |
| 46 | |
| 47 | static const int8_t index_table1[] = { |
| 48 | -1, 4, -1, 4 |
| 49 | }; |
| 50 | |
| 51 | static const int8_t index_table2[] = { |
| 52 | -1, -1, 2, 6, -1, -1, 2, 6 |
| 53 | }; |
| 54 | |
| 55 | static const int8_t index_table3[] = { |
| 56 | -1, -1, -1, -1, 1, 2, 4, 6, -1, -1, -1, -1, 1, 2, 4, 6 |
| 57 | }; |
| 58 | |
| 59 | static const int8_t index_table4[] = { |
| 60 | -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6, |
| 61 | -1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 2, 2, 4, 5, 6 |
| 62 | }; |
| 63 | |
| 64 | static const int8_t index_table5[] = { |
| 65 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 66 | 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6, |
| 67 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 68 | 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 5, 5, 6, 6 |
| 69 | }; |
| 70 | |
| 71 | static const int8_t index_table6[] = { |
| 72 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 73 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 74 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, |
| 75 | 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, |
| 76 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 77 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, |
| 78 | 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, |
| 79 | 2, 2, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6 |
| 80 | }; |
| 81 | |
| 82 | static const int8_t *const step_index_tables[] = { |
| 83 | index_table1, index_table2, index_table3, |
| 84 | index_table4, index_table5, index_table6 |
| 85 | }; |
| 86 | |
| 87 | static av_cold int decode_init(AVCodecContext *avctx) |
| 88 | { |
| 89 | int start_pos; |
| 90 | |
| 91 | avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
| 92 | |
| 93 | if (predict_table_init) |
| 94 | return 0; |
| 95 | |
| 96 | for (start_pos = 0; start_pos < 64; start_pos++) { |
| 97 | unsigned int dest_pos, table_pos; |
| 98 | |
| 99 | for (table_pos = 0, dest_pos = start_pos; |
| 100 | table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table); |
| 101 | table_pos++, dest_pos += 64) { |
| 102 | int put = 0, count, table_value; |
| 103 | |
| 104 | table_value = ff_adpcm_step_table[table_pos]; |
| 105 | for (count = 32; count != 0; count >>= 1) { |
| 106 | if (start_pos & count) |
| 107 | put += table_value; |
| 108 | table_value >>= 1; |
| 109 | } |
| 110 | predict_table[dest_pos] = put; |
| 111 | } |
| 112 | } |
| 113 | predict_table_init = 1; |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static int decode_frame(AVCodecContext *avctx, void *data, |
| 119 | int *got_frame_ptr, AVPacket *pkt) |
| 120 | { |
| 121 | GetBitContext gb; |
| 122 | AVFrame *frame = data; |
| 123 | int16_t pcm_data[2]; |
| 124 | uint32_t samples; |
| 125 | int8_t channel_hint[2]; |
| 126 | int ret, chan; |
| 127 | int channels = 1; |
| 128 | |
| 129 | if (pkt->size < 13) |
| 130 | return AVERROR_INVALIDDATA; |
| 131 | |
| 132 | if ((ret = init_get_bits8(&gb, pkt->data, pkt->size)) < 0) |
| 133 | return ret; |
| 134 | |
| 135 | samples = get_bits_long(&gb, 32); |
| 136 | if (samples == 0xffffffff) { |
| 137 | skip_bits_long(&gb, 32); |
| 138 | samples = get_bits_long(&gb, 32); |
| 139 | } |
| 140 | |
| 141 | if (samples > pkt->size * 2) |
| 142 | return AVERROR_INVALIDDATA; |
| 143 | |
| 144 | channel_hint[0] = get_sbits(&gb, 8); |
| 145 | if (channel_hint[0] & 0x80) { |
| 146 | channel_hint[0] = ~channel_hint[0]; |
| 147 | channels = 2; |
| 148 | } |
| 149 | avctx->channels = channels; |
| 150 | avctx->channel_layout = (channels == 2) ? AV_CH_LAYOUT_STEREO |
| 151 | : AV_CH_LAYOUT_MONO; |
| 152 | pcm_data[0] = get_sbits(&gb, 16); |
| 153 | if (channels > 1) { |
| 154 | channel_hint[1] = get_sbits(&gb, 8); |
| 155 | pcm_data[1] = get_sbits(&gb, 16); |
| 156 | } |
| 157 | |
| 158 | frame->nb_samples = samples; |
| 159 | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
| 160 | return ret; |
| 161 | |
| 162 | for (chan = 0; chan < channels; chan++) { |
| 163 | uint16_t *dest = (uint16_t *)frame->data[0] + chan; |
| 164 | int step_index = channel_hint[chan]; |
| 165 | int output = pcm_data[chan]; |
| 166 | int sample; |
| 167 | |
| 168 | for (sample = 0; sample < samples; sample++) { |
| 169 | int lookup_size, lookup, highbit, lowbits; |
| 170 | |
| 171 | step_index = av_clip(step_index, 0, 88); |
| 172 | lookup_size = size_table[step_index]; |
| 173 | lookup = get_bits(&gb, lookup_size); |
| 174 | highbit = 1 << (lookup_size - 1); |
| 175 | lowbits = highbit - 1; |
| 176 | |
| 177 | if (lookup & highbit) |
| 178 | lookup ^= highbit; |
| 179 | else |
| 180 | highbit = 0; |
| 181 | |
| 182 | if (lookup == lowbits) { |
| 183 | output = get_sbits(&gb, 16); |
| 184 | } else { |
| 185 | int predict_index, diff; |
| 186 | |
| 187 | predict_index = (lookup << (7 - lookup_size)) | (step_index << 6); |
| 188 | predict_index = av_clip(predict_index, 0, 5785); |
| 189 | diff = predict_table[predict_index]; |
| 190 | if (lookup) |
| 191 | diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1); |
| 192 | if (highbit) |
| 193 | diff = -diff; |
| 194 | |
| 195 | output = av_clip_int16(output + diff); |
| 196 | } |
| 197 | |
| 198 | *dest = output; |
| 199 | dest += channels; |
| 200 | |
| 201 | step_index += step_index_tables[lookup_size - 2][lookup]; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | *got_frame_ptr = 1; |
| 206 | |
| 207 | return pkt->size; |
| 208 | } |
| 209 | |
| 210 | AVCodec ff_adpcm_vima_decoder = { |
| 211 | .name = "adpcm_vima", |
| 212 | .long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"), |
| 213 | .type = AVMEDIA_TYPE_AUDIO, |
| 214 | .id = AV_CODEC_ID_ADPCM_VIMA, |
| 215 | .init = decode_init, |
| 216 | .decode = decode_frame, |
| 217 | .capabilities = CODEC_CAP_DR1, |
| 218 | }; |
| 219 | |
| 220 | AVCodec ff_vima_decoder = { |
| 221 | .name = "vima", |
| 222 | .long_name = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"), |
| 223 | .type = AVMEDIA_TYPE_AUDIO, |
| 224 | .id = AV_CODEC_ID_ADPCM_VIMA, |
| 225 | .init = decode_init, |
| 226 | .decode = decode_frame, |
| 227 | .capabilities = CODEC_CAP_DR1, |
| 228 | }; |